Dynamometer.



W. L. HAMILTON.

DYNAMOMETER APPLICATION FILED AUG-14,1916.

Patented July 10, 1917.

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W. L. HAMILTON.

DYNAMOMETER.

APPLICATION FILED AUG.14, I916. I I msmw, Patented July 10, 1917.

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I To all whom it may concern Be it known that l, WALTER L. HAMm'roN, a citizen of the United States of America, residin in the city of Holyoke, count of Hemp en, and State of Massachusetts, ave invented certain new and useful Improvements in Dynamometers, of which the folhill lowing is a specification.

This invention relates to improvements 1n dynamometers and more particularly to an advantageous arrangement ofindicating mechanism for dynamometers of the socalled spiral spring type.

An object of he invention is to provide h ing characterized by uniform increments of 'movement of the indicating mechanism for uniform increments of load u on the driven element and by moving the in icating means by said relative. movement with a minimum amount of efi'ort.

Another object of the invention is to provide an improved dynamometer having driving and driven elements in line with one another, the former arranged to drive the latter through the intermediary of a resilient connection, and means to indicate by the relative movement between said elements the tension of said connection and thus the load on said driven element.

A further object of the invention is to rovide adynamometer of generally simplied and im rovedmechanical structure.

Other objects and'advantages will appear in the description to follow and in the annexed claims. r

For the purpose of illustrating one manner in which the invention may be applied in practice, a preferred embodiment thereof, with detailed variations, is shown in the ac companying drawings, in which Figure 1 is a top plan view of the dynamometer; 1

Fig. 2 is a sectional elevation taken on the line 2-2 of Fig. 1;

Figs. 3 and 4 are cross sectional views a a aam rm re nt' Patented July to, ram. Application filed must it, me. semi at. 11am.

taken on the lines 33 and 4--4, respectively, of Fig. 1;

Fig. 5 is a fragmentar plan-view showing a'modification in the in icating mechanism; Fig. 6 is a partial plan view showing a modification in the arrangement of parts of as shown in Figs. 1 and 2 to a base 6.

Shaft 10 has a portion 11 of reduced diameter and another portion 12 which is of less dlameter than the portion 11. Rotatably mounted on the latter is a sleeve 13 which is mounted in the left-hand pair of bearings a and thereby supports the other end of shaft 10. Fixed to sleeve 13, as shown in Fig. 2, is a pulley 14 which is adapted to drive the machine to be tested by the dynamometer. Fixed to sleeve 13 is a cup-shaped member 15 and secured to shaft 10 is a sleeve 16 which extends within member 15 and is connected to the inner periphery thereof by a spiral spring 17 as best shown in Fig. 4.

' It will thus be seen that shaft 10 and sleeve 13 are. connected by resilient means so that, if power is applied to ulley 11, a machine belted to pulley 14 will be driven through the vintermediary of the spring. Furthermore, the spring 17 will be wound up to some extent so that there will be a relative rotation of shaft 10 and sleeve 13 and the amount of this rotation will be a measure of the power required to drive the machine conjacent the member 11 are secured other:

pulleys 22 and 23, respectively. Slidable on member. 12 is a disk 24 which is movable ad-' .jacent a aduated scale 25 fixed to a suitable brac et on base '5. Disk 24 is arranged to be propelled back and forth on member 12 by means of a cord 26, both ends of which are connected to the drum at 27.

Start with one end from the point 27,

1 the cor passes over the periphery of drum mf-paralle loosely through a hole 28 (-Fig. 3) in disk 24 18', downwardly around pulley 21, upwardl over p'ulle' 22 then horizontall to the le relation with mem r 12, and

' to and around a pulley 29 fixed on the end asses hori- ;zontally to the right, is looped t rough two ey 23, then upwardly over ereafter downwardly, being wound around the drum in an opposite direction to the first end of the cord and seto the drum at 27. It will be evident that-as drum 18 turns relatively to arm 19 the cord 26 will be wound up at one end and unwound at the other end, and by the looped connection with holes 30 will positively move the disk 24: in both directions.

The arrangement described is important since the disk 24 is movable with a minimum of friction. Movable measuring elements have been provided which are positively moved in one direction but are provided with springs or the like to secure the return movement. The present construction avoids the necessity for a spring and eliminates the friction loss incident to the use of the spring.

Furthermore, by dispensing with the spring the scale 25 may lie-uniformly graduated as against the non-uniform graduations obcreasing the diameter of drum 18.

' tained when a spring is employed. ,It is particularly to be noted that the dynamometer described may readily be made to secure as close accuracy as may be, desired simply by elongating the member 12 and in- If'desirable, the dynamometer may be provided with a recording mechanism, as shown in Fig. 5, so that a continuous and permanentrecord of the power used by a particular machine may be'obtained. Fixed in and extending between spaced brackets (1 secured' to base I) is a rod 31 upon which a member 32 is slidable. The latter carries a suitable marking pen 33 and is engaged by disk 24, as shown, so that as the latter moves on'part'12 the pen 33 is moved horizontally across a record sheet 34 which is propelled uniformly by a suitable clock mechanism e.

The curve 35 traced on sheet 34: thus repre-- sents power plotted a ainst time and gives a continuous record 0 the power consumption of theymachine tested.

' Where the dynamometer is used for testing machines already in place in factories, I

provide a modified arrangement of parts whichis illustrated in Figs. 6 and 7. .For

such use, it is desirable to have the driving and driven pulleys directly in line with one another, since then the dynamometer maybe simply interposed between the main dr1ve shaft and the machine to be tested without the necessity (if the arrangement shown in Fig. 1 is used) of fastening an additional pulley on the main driving shaft or moving the machine to be tested. The driving ulley 11 is replaced by a spur gear-37 w ich meshes with a similar gear 38 on a countershaft 39 rotatably supported in bearings f secured to base 6. The driving ulley 11 is fixed to shaft 39 directly behind pulley 14. In operation, power is applied to pulley 11 and the machine to be tested is connected to pulley 14. The spring 17 is wound up until its tension just balances the load on the machine to be tested after which the machine is driven just as if the shaft 10 and sleeve 13 were rigidly connected. The relative turning movement between the shaft 10 and'sleeve 13 causes the disk 24 to move axially along the member as already described and the extent of such movement, as indicated on-scale 25, is a measure of the power consumption of the machine tested. Obviously, the pulley -11 may be the driven, and pulley 151 the driving members, but the described arrangement is preferred since by having the driven ulley nearest the indicating mechanism, t e friction losses of the dynamometer are not included in the reading on scale 25' or curve 35.

The invention has been described in a preferred form with detailedvariations for illustrative pur oses, but the scope of the invention is de rather than by the foregoing description.

What I claim is- 1. A dynamometer, comprising, a driving element, a driven element, a resilient connection between said elements arranged by its tension to balance the load on the driven element, a slidable indicator, and flexible means connecting the driving and driven elements and said indicator, said means being operable by the relative movement between said elements to positively move said indicator in both directions to indicate the load on the driven element.

ed by the appended claims 2. A dynamometer, comprising, a driving shaft, a sleeve rotatable thereon, a load driving member on the sleeve, a resilient means connecting the sleeve and shaft, an indicator slidable axially on the latter, a drum on the sleeve, and flexible means connecting the drum and indicator to positively propel the latter-back and forth upon the shaft to inranged to be placed under tension and by its tension to balance the load on the driven shaft, and means operable by the relative turning movement between the shafts to indicate the load upon the driven shaft. 7 I

4:. A dynamometer, comprising, a'driving shaft, a sleeve rotatable thereon, a resilient means connecting the sleeve and shaft, a drum on the sleeve, an arm on the shaft adjacent the' drum, pulleys on said arm, a pulley on the end of the shaft at a distance from said arm, a flexible belt looped around the WALTER L; HAMlLTON. 

